Renal - Congenital Abnormalities; Acute Renal Failure

Question 1

What is the most common congenital renal anomaly?

Answer 1

Horseshoe kidney

Question 2

Horseshoe kidneys are typically conjoined at the _______ renal ______.

Answer 2

Horseshoe kidneys are typically conjoined at the lower renal pole.

Question 3

In its ascent from the pelvis, horseshoe kidneys most commonly get caught where / on what?

Answer 3

The inferior mesenteric artery

(IMA root)

Question 4

Although horseshoe kidneys are typically ______, there may be some increased risk of certain ______s.

Answer 4

Although horseshoe kidneys are typically benign, there may be some increased risk of certain malignancies.

Question 5

Renal _______ refers to the absence of one or both kidneys.

Answer 5

Renal agenesis refers to the absence of one or both kidneys.

Question 6

Unilateral renal agenesis leads to ___________ of the existing kidney; hyperfiltration leads to increased risk of ______ ______ later in life.

Answer 6

Unilateral renal agenesis leads to hypertrophy of the existing kidney; hyperfiltration leads to increased risk of renal failure later in life.

Question 7

Bilateral renal agenesis leads to what condition(s)?

Answer 7

Potter’s syndrome

Question 8

What noninherited, congenital malformation of the renal parenchyma is characterized by cysts and abnormal tissue?

Answer 8

Dysplastic kidney

Question 9

Dysplastic kidneys are usually ____lateral.

Answer 9

Dysplastic kidneys are usually unilateral.

Question 10

When bilateral renal cysts are present, polycystic kidney disease must be differentiated from what?

Answer 10

Dysplastic kidneys

Question 11

Polycystic kidney disease leads to bilateral enlarged kidneys with cysts in which: the renal cortex or the renal medulla?

Answer 11

Both

Question 12

Autosomal dominant cases of polycystic kidney disease are associated with mutations in what two genes?

Answer 12

(1) APKD1
(2) APKD2

Question 13

Autosomal dominant polycystic kidney disease typically presents first in __________ (age group) as worsening renal failure, hypertension, and hematuria.

Answer 13

Autosomal dominant polycystic kidney disease typically presents first in young adults as worsening renal failure, hypertension, and hematuria.

Question 14

Autosomal recessive polycystic kidney disease typically presents first in __________ (age group) as worsening renal failure, hypertension, and hematuria.

Answer 14

Autosomal recessive polycystic kidney disease typically presents first in infants as worsening renal failure and hypertension.

Question 15

Autosomal _________ polycystic kidney disease typically presents in young adults as worsening renal failure, hypertension, and hematuria.

Answer 15

Autosomal dominant polycystic kidney disease typically presents in young adults as worsening renal failure, hypertension, and hematuria.

Question 16

Autosomal _________ polycystic kidney disease typically presents in infants as worsening renal failure and hypertension.

Answer 16

Autosomal recessive polycystic kidney disease typically presents in infants as worsening renal failure and hypertension.

Question 17

True/False.

Newborns with autosomal recessive polycystic kidney disease can present with Potter’s syndrome.

Answer 17

True.

Question 18

Is autosomal dominant polycystic kidney disease associated with high- or low-renin hypertension?

Answer 18

High-renin

Question 19

What are the main presenting S/Sy of a patient with autosomal dominant polycystic kidney disease?

Answer 19

Hypertension

Worsening renal failure

Hematuria

Question 20

Autosomal recessive kidney disease is associated with major damage to what organ besides the kidneys?

Answer 20

The liver

(associated with hepatic fibrosis and hepatic cysts)

Question 21

Autosomal dominant kidney disease is associated with what extra-renal pathologies?

Answer 21

Berry aneurysms;

hepatic cysts;

mitral valve prolapse

Question 22

A newborn presents with hypertension, portal hypertension, and markedly elevated creatinine; exam shows bilateral renal cysts and hepatic fibrosis.

What is the diagnosis?

Answer 22

Autosomal recessive polycystic kidney disease

Question 23

What autosomal dominant disease results in atrophic kidneys, worsening renal failure, and medullary (but not cortical) renal cysts?

Answer 23

Medullary cystic kidney disease

Question 24

Medullary cystic kidney disease leads to atrophic kidneys with cysts in which: the renal cortex or the renal medulla or both?

Answer 24

The medulla only

Question 25

Identify which of the following congenital renal abnormalities results in worsening renal failure: ## Footnote **Autosomal dominant polycystic kidney disease** **Autosomal recessive polycystic kidney disease** **Medullary cystic kidney disease**

Answer 25

All three

Question 26

Acute renal failure is a severe _________ in kidney function that develops over a period of a few \_\_\_\_\_s.

Answer 26

Acute renal failure is a severe **_decrease_** in kidney function that develops over a period of a few **_day_**s.

Question 27

The hallmarks of acute renal failure include: \_\_\_\_\_\_**emia**, increased _______ and _______ (lab values), and (often) \_\_\_\_**uria**.

Answer 27

The hallmarks of acute renal failure include: **_azo_****temia**, increased **_BUN_** and **_creatinine_**, and **_olig_****ur****ia**.

Question 28

A patient presents with azotemia, increased BUN and creatinine, and oliguria. Her S/Sy have been increasing rapidly over the past few days. What is the immediate diagnosis?

Answer 28

Acute renal failure

Question 29

Acute renal failure can be divided into what three forms of azotemia (based on etiology)?

Answer 29

**Pre**renal **Intra**renal **Post**renal

Question 30

Prerenal azotemia is a form of acute renal failure that most often occurs due to decreased what?

Answer 30

**Renal blood flow** | (e.g. due to cardiac failure)

Question 31

Prerenal azotemia is a form of acute renal failure that often occurs due to __________ GFR.

Answer 31

Prerenal azotemia is a form of acute renal failure that often occurs due to **_decreased_** GFR.

Question 32

Is tubular function increased, decreased, or preserved in cases of acute renal failure due to prerenal azotemia?

Answer 32

Preserved | (unchanged)

Question 33

In cases of prerenal azotemia, serum BUN:creatinine \> \_\_\_\_\_.

Answer 33

In cases of prerenal azotemia, serum BUN:creatinine \> **_15_**.

Question 34

In cases of prerenal azotemia, tubular function is preserved; FENa \< \_\_\_\_% and osmolarity_urine \> ____ mOsm/kg.

Answer 34

In cases of prerenal azotemia, tubular function is preserved; FENa \< **_1_**% and osmolarity_urine \> **_500_** mOsm/kg.

Question 35

Postrenal azotemia is a form of acute renal failure that most often occurs due to what?

Answer 35

**Urinary tract obstruction** (downstream from the kidney; e.g. ureter obstruction)

Question 36

Postrenal azotemia is a form of acute renal failure that often results in a __________ GFR.

Answer 36

Postrenal azotemia is a form of acute renal failure that often results in a **_decreased_** GFR.

Question 37

Is tubular function increased, decreased, or preserved in the early cases of acute renal failure due to postrenal azotemia?

Answer 37

Preserved | (unchanged)

Question 38

In early cases of postrenal azotemia, serum BUN:creatinine ___ 15.

Answer 38

In early cases of postrenal azotemia, serum BUN:creatinine **\>** 15.

Question 39

In early cases of postrenal azotemia, tubular function is preserved; FENa \< \_\_\_\_% and osmolarity_urine \> ____ mOsm/kg.

Answer 39

In early cases of postrenal azotemia, tubular function is preserved; FENa \< **_1_**% and osmolarity_urine \> **_500_** mOsm/kg.

Question 40

Is tubular function increased, decreased, or preserved in late cases of acute renal failure due to postrenal azotemia?

Answer 40

**Decreased** | (due to tubular damage)

Question 41

In late cases of postrenal azotemia, serum BUN:creatinine ___ 15.

Answer 41

In late cases of postrenal azotemia, serum BUN:creatinine **\<** 15.

Question 42

In late cases of postrenal azotemia, tubular function is decreased; FENa \> \_\_\_\_% and osmolarity_urine \< ____ mOsm/kg.

Answer 42

In late cases of postrenal azotemia, tubular function is decreased; FENa \> **_2_**% and osmolarity_urine \< **_500_** mOsm/kg. ***(Decreased sodium reabsorbtion and decreased ability to concentrate urine)***

Question 43

**True/False**. Early cases of acute renal failure and postrenal azotemia are characterized by no change in tubular function *(BUN:creatinine \> 15; Fractional excretion of Na \< 1%; osmolarity_urine \> 500 mOsm/kg)*.

Answer 43

True.

Question 44

**True/False**. Late cases of acute renal failure and postrenal azotemia are characterized by no change in tubular function *(BUN:creatinine \> 15; Fractional excretion of Na \> 1%; osmolarity_urine \> 500 mOsm/kg)*.

Answer 44

**False**. Late cases of acute renal failure and postrenal azotemia are characterized by ***a decrease*** in tubular function *(BUN:creatinine* **\<** *15; Fractional excretion of Na \>* **2***%; osmolarity_urine* **\<** *500 mOsm/kg)*.

Question 45

A patient presents with acute renal failure (azotemia, oliguria), decreased BUN reabsorption (serum BUN:creatinine \< 15), fractional excretion of sodium \> 2%, and urine \< 500 mOsm/kg. Identify which of the following could potentially match the diagnosis: **Prerenal azotemia** **Early postrenal azotemia** **Late postrenal azotemia** **Acute tubular necrosis**

Answer 45

**​Late postrenal azotemia**; ## Footnote **acute tubular necrosis**

Question 46

Name three causes of acute renal failure due to _intrarenal_ azotemia.

Answer 46

(1) Acute tubular necrosis (2) Acute interstitial nephritis (3) Renal papillary necrosis

Question 47

What etiology is the most common cause of acute renal failure?

Answer 47

Acute tubular necrosis

Question 48

In acute tubular necrosis, _________ epithelial cells obstruct the tubules and _________ GFR.

Answer 48

In acute tubular necrosis, **_necrotic_** epithelial cells obstruct the tubules and **_decrease_** GFR.

Question 49

What is seen in the urine in cases of acute tubular necrosis?

Answer 49

Brown, granular casts

Question 50

The etiology of acute tubular necrosis is typically either \_\_\_\_\_\_mic or \_\_\_\_\_\_xic.

Answer 50

The etiology of acute tubular necrosis is typically either **_ische_**mic or **_nephroto_**xic.

Question 51

_Ischemic_ acute tubular necrosis is often preceded by what form of acute renal failure?

Answer 51

Prerenal azotemia

Question 52

Which two portions of the nephron are most susceptible to damage in cases of _ischemic_ acute tubular necrosis?

Answer 52

(1) **Proximal tubule** (2) **Medullary segment of the thick ascending limb**

Question 53

If a case of acute tubular necrosis is not due to ischemic conditions, it is likely due to what?

Answer 53

Nephrotoxic agents

Question 54

Which portion of the nephron is particularly susceptible to damage in cases of _nephrotoxic_ acute tubular necrosis?

Answer 54

The proximal tubule

Question 55

Name a few causes of nephrotoxic acute tubular necrosis. (Most common first)

Answer 55

**Aminoglycosides**; heavy metals; myoglobinuria (e.g. from crush injuries); ethylene glycol; radiocontrast dye; urate (tumor lysis syndrome)

Question 56

How can acute tubular necrosis due to tumor lysis syndrome (elevated serum urate) be prevented prior to initiating chemotherapy?

Answer 56

**Hydration**; **allopurinol** administration

Question 57

Describe the lab results seen in acute tubular necrosis: Casts: Elevated serum substances: Serum pH: Urine frequency:

Answer 57

Describe the lab results seen in acute tubular necrosis: Casts: **_Brown, granular_** Elevated serum substances: **_BUN, creatinine, potassium_** Serum pH: **_metabolic acidosis_** Urine frequency: **_oliguria_**

Question 58

The oliguria associated with acute tubular necrosis can last 2 - 3 ________ before recovery.

Answer 58

The oliguria associated with acute tubular necrosis can last 2 - 3 **_weeks_** before recovery. ## Footnote *(**T****ubular cells are stable cells that take time to recover.**)*

Question 59

A patient presents with the following lab and clinical results after starting chemotherapy: **Casts: Brown, granular** **Elevated serum substances: BUN, creatinine, potassium** **Serum pH: metabolic acidosis** **Urine frequency: oliguria** What is the diagnosis?

Answer 59

**Acute tubular necrosis** (due to the elevated urate associated with tumor lysis syndrome)

Question 60

**True/False**. Acute tubular necrosis is typically irreversible, although not likely to be fatal if not treated.

Answer 60

**False**. Acute tubular necrosis is typically **_reversible_**, although _***dialysis is often required*** ***to prevent fatality due to electrolyte imbalances***_.

Question 61

What are the most common causes of acute interstitial nephritis?

Answer 61

Drug-induced hypersensitivity

Question 62

Acute interstitial nephritis typically affects what part(s) of the kidney?

Answer 62

The **interstitium** and **tubules**

Question 63

What medications are the most common causes of acute interstitial nephritis?

Answer 63

**NSAIDs**; **penicillin**; **diuretics**

Question 64

How is acute interstitial nephritis typically treated?

Answer 64

Typically resolves with cessation of the inducing medication

Question 65

Acute interstitial nephritis may progress to what?

Answer 65

Renal papillary necrosis

Question 66

What are the S/Sy of acute interstitial nephritis?

Answer 66

Oliguria; fever; rash

Question 67

What may be seen in the urine in cases of acute interstitial nephritis?

Answer 67

Eosinophils

Question 68

Acute interstitial nephritis is typically seen how long after starting a medication (e.g. NSAIDs, penicillin, or diuretics)?

Answer 68

Days to weeks

Question 69

Name a few common etiologies of renal papillary necrosis (most important will be bolded).

Answer 69

(1) **Chronic analgesic use** (2) Diabetes mellitus (3) Sickle cell (trait or disease) (4) Severe acute pyelonephritis

Question 70

What are some of the S/Sy of renal papillary necrosis?

Answer 70

Gross hematuria; flank pain

Question 71

Which is the most common of the three congenital cystic renal diseases?

Answer 71

ADPKD

Question 72

ARPKD is caused by a mutation in the ______ gene on chromosome 6.

Answer 72

ARPKD is caused by a mutation in the ***_PKHD1_*** gene on chromosome 6.

Question 73

Which of the congenital cystic kidney diseases presents in infants as hypertension, lung hypoplasia, and dilated medullary and cortical **collecting ducts**?

Answer 73

ARPKD

Question 74

Which is the most common cystic renal disease in children?

Answer 74

Multicystic dysplastic kidney disease

Question 75

What is the histological hallmark of multicystic dysplastic kidney disease?

Answer 75

Ducts and tubules **surrounded by cuffs of cellular mesenchyme**

Question 76

**True/False**. Renal cysts are very common.

Answer 76

True.

Question 77

Name the most common ureteral anomaly.

Answer 77

Double and/or bifid ureter

Question 78

Describe the histology of extrophy of the bladder.

Answer 78

Squamous or colonic glandular metaplasia (Increased risk of adenocarcinoma)

Question 79

What is the most common cause of bladder outlet obstruction in male infants?

Answer 79

Posterior urethral valves